Antivibration resilient buffers are known that are made from a rolled-up knitted metal strip to form an annular or a solid cylindrical preform which is subsequently compressed axially in a mold so as to tangle together the stitches of the knit and thus impart cohesion to the buffer adapted to the loads to which the buffer is subjected in use.
For given knit density, the deflections to which the buffer is subjected under load increase with increasing load and also with increasing initial no-load height of the buffer.
To enable the buffer to withstand high static loads while nevertheless being capable of bending under the effect of momentary overloads, it is necessary for the buffer to be tall relative to its outside diameter. The ratio of height to diameter can thus reach and even easily exceed unity.
When a sleeve, and more particularly a sleeve that is tall relative to its diameter, is subjected to a high axial load, it tends to deform with its side surface then taking up a barrel-shaped appearance. This gives rise to a loss of buffer stiffness and its performance is degraded.
A past proposal for mitigating this drawback consists in enveloping the metal wire strip or the buffer itself in a thin metal sheet or in disposing metal rings around the buffer. Those techniques have the advantage of imparting good radial stiffness, but they reduce the axial flexibility of the buffer whose antivibration properties suffer accordingly.
Proposals have also been made to place a thin helically-wound metal wire around the buffer which becomes buried in the spiral-wound metal knit on axial compression. That solution is satisfactory as to the radial stiffness obtained and as to retaining the axial flexibility of the buffer, however it is relatively expensive and complex to implement